Power transmitting device



May 17, 1955 c. J. WERNER 2,708,373

POWER TRANSMITTING DEVICE Filed Sept. 27, 1951 IN V EN TOR. 4541. \//N (I MIG/V58 United States Patent 2,7as,s7s

POWER TRANSMiTTlNG DEVICE Calvin J. Werner, Dayton, Ohio, assignor to General Motors Corporation, Detroit, Mich, a corporation of Delaware Application September 27, 1951, Serial No. 243,499

3 Claims. (Cl. 74-242.8)

This invention relates to an improved power transmitting device.

It is among the objects of the present invention to provide a self-aligning power transmitting device consisting of an intermediate shaft supporting two pulleys which are respectively connected by belts to a driving and to a driven pulley, arranged relatively one to the other in any suitable manner.

A further object of the present invention is to provide a power transmitting device as defined above, said device being operative automatically to tighten or to maintain said belts operatively taut. This invention lends itself advantageously to reverse operation of the driven member or fan in this instance by the single expedient of reversing the application of the belt on the driving pulley thereby avoiding the necessity of a reversible power unit.

These objects are accomplished by movably suspending the journal box in which the intermediate shaft, supporting the two pulleys, is rotatably supported. The suspension means may be any suitable member, preferably coil springs, which will permit the journal box to move automatically to bring the belt connected pulleys in operative alignment, the advantage of the use of springs being that they are adapted to hold the belts taut by exerting a pulling effort.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings wherein a preferred embodiment of the present invention is clearly shown.

In the drawings:

Fig. 1 is a view showing the present invention applied to an electric motor driven fan especially adapted for window use.

Fig. 2 is a side view of the device shown in Fig. 1.

Fig. 3 is a perspective of the mechanism shown in Fig. 1.

The improved power transmitting device, the subject matter of the present invention, may advantageously be used in a window fan where the air circulating fan is rotatably supported in a housing or shroud and driven by an electric motor through a belt connection. The simplest way of transmitting the power from a motor to a fan is to have the motor rotor shaft and the shaft upon which the fan is carried substantially parallel, each being provided with a pulley operatively connected by a belt. In window fans the housing or shroud must be comparatively narrow so as not to extend beyond the inside or the outside edges of the window frame. Usually the motor to drive the fan has an overall length greater than the width of the shroud and to avoid extension of the driving shaft of the motor beyond the one side of the shroud, which is generally covered with a protective screen, a bulge is provided at a front corner of the housing or shroud into which the motor may extend to compensate for the length thereof. This bulge, in what should be a normally straight and fiat front on 2,708,373 ?atenteti May 17, 1955 the housing, detracts from its appearance and therefore is undesirable.

In order to eliminate the bulge so that the outside appearance of the window fan housing is not marred thereby, the electric motor may be mounted as shown in Figs. 1 and 3 of the drawings so that no portion thereof extends beyond the confines of the shroud. This displaces the motor from the fan pulley so that the rotor shaft of the motor is angularly arranged relatively to the fan shaft and its pulley thereby requiring a unique power transmitting drive connection between the motor and the fan.

The present invention provides such a power transmitting connection.

Referring to the drawings, the housing or shroud of the window fan is rectangular in shape preferably square and of the width comparative to the width of a window frame in an ordinary dwelling. The one side of this shroud has a face plate 21 provided with a circular opening 22 in which the fan blades 23 rotate, this opening 22 being usually covered with any suitable screen which acts as a safety device. Suitable rigid uprights 24 are secured within the shroud for supporting the journal box 25 in which the shaft to which the fan blades 23 are attached is rotatably supported. At the end of the shaft opposite the fan blade 23 there is attached a pulley 26 to be driven by the electric motor 30 which, as shown in the drawings, is mounted within the housing on one side thereof the rotor shaft of said motor being longitudinal of the side on which the motor is mounted. The rotor shaft of the motor 38 has a pulley 31 attached thereto, the axis of which is substantially at right angles to the axis of the shaft supporting the fan pulley 26.

In order to connect the driving motor 31) with the fan 23 or more specifically the pulley 31 of the motor with the fan pulley 26, the power transmitting mechanism of the present invention is particularly adaptable, especially in an installation of this kind. This power transmitting mechanism consists of a journal box 35 rotatably supporting a shaft at one end of which a pulley 36 is attached and at the other end a pulley 37 so that both pulleys 36 and 37 rotate with the shaft supported within the journal box 35. This journal box has an angular extension 38 to which corresponding ends of the two springs 39 and 49 are attached, the other ends of these springs being anchored to the sides of the shroud whereby said springs movably support the journal box 35 within the shroud or housing 24 The spring 39 has its end attached to the angular extension 38 of the journal box 35 adjacent the pulley 37 which, as shown in Fig. 1, is connected with the pulley 31 of the motor by belt 45. The other end of spring 39 is secured to the side of the shroud opposite the side on which the motor is mounted and at such a location so that the axial stretching line of spring 39 is substantially in parallelism with the belt 45 or in such a manner that the spring 39 exerts a pull upon the journal box 35 lengthwise of and in substantial alignment with the belt 4-5 thereby automatically holding the belt 45 taut and at the same time holding the pulley 37 in operative alignment with its connected motor pulley 31. in like fashion spring is attached to another side of the shroud or housing 29 and to the extension 38 adjacent pulley 36, so that its axial stretching line is in substantial parallelism with the belt 48 connecting pulleys 36 and 26, the spring 40 exerting a pulling or stretching force upon the belt 48 substantially lengthwise thereof to maintain it taut and at the same time holding the journal box 35 in suspension so that pulleys 36 and 26 are in operative alignment.

From the aforegoing it may be seen that springs 39 and 49 movably suspend the journal box 35 within the a journal box 35 within the shroud or housing 211 so that pulley alignment is substantially maintained. However,

it has been found that coil springs, as shown are most preferable in that they exert their forces and perform their functions under more varied circumstances and shiftable positions than would many other means for movably supporting the journal box 35. It will, of course, be understood that the side of the casing opposite the side provided with the opening 22 is covered witlia protective screen thus preventing any of the working parts within the housing from extending beyond this protective covering.

While the embodiment of the present invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted.

What is claimed is as follows:

1. A power transmitting device comprising in combination, a driving pulley, a driven pulley, a journal box '1 supporting a rotating shaft having a pulley attached at each end thereof, a belt, connecting one shaft pulley with the driving pulley and another belt connecting the other shaft pulley with the driven pulley, and plural resilient suspension means suspending said journal box from a stationary support for free spatial movement, eac Suspension means acting on said, journal box in a direction substantially aligned with the belt engaging the shaft pulley adjacent the respective suspension means whereby to maintain the pulley connected belts taut and each pair of belt connected pulleys in operative alignment.

. 2. A power transmitting device comprising in combination, a driving pulley, a driven pulley, a journal box supporting a rotatable shaft having a pulley attached at each end thereof, a belt connecting one shaft pulley with the driving pulley and another belt connecting the other shaft pulley with the driven pulley, and coil springs attached to the journal box adjacent each of the respective pulleys thereon and to a stationary support, said springs yieldably suspending the box from the support for free spatial movement, the tensional axis of each spring being in substantial alignment with the belt nearest adjacent the respective spring to maintain thereby the belts taut and each pair of belt connected pulleys in operative alignment.

3. A power transmitting device comprising in combination, a driving pulley, a driven pulley, a journal box supporting a rotatable shaft having a pulley attached at each end thereof, a belt connecting one shaft pulley with the driving pulley and another belt connecting the other shaft pulley with the driven pulley, and coil springs attached to the journal box adjacent each of the respective pulleys thereon and to a stationary support, said springs yieldably suspending the box from the support for free spatial movement, the tensional axis of each spring being in substantial linear alignment with the belt nearest adjacent the respective spring to maintain thereby. the belts taut and each pair of belt connected pulleys inoperative alignment.

References Cited in the file of this patent UNITED STATES PATENTS 28,353 Davis May 22, 1860 1,795,313 Nies Mar. 10, 1931 2,158,556 Wesche May 16, 1939 2,207,073 Shields July 9, 1940 2,564,132 Scott Aug. 14, 1951 FOREIGN PATENTS 360,471 Germany Oct. 3, 1922 116,473 Sweden May 28, 1946 116,872 Switzerland Oct. 1, 1926 nip- 

